KR20240157004A - Touch driving circuit, touch display device, and touch driving method thereof - Google Patents

Abstract

Embodiments of the present invention relate to a touch driving circuit, a touch display device, and a touch driving method, and more specifically, to a touch driving circuit, a touch display device, and a touch driving method which can divide a touch sensing type into an active mode and an idle mode and reduce power consumption in the idle mode. In addition, embodiments of the present invention can provide a touch driving circuit, a touch display device, and a touch driving method which can reduce power consumption by shortening a touch driving period in the idle mode. In addition, embodiments of the present invention can provide a touch driving circuit, a touch display device, and a touch driving method which can reduce power consumption by shortening a touch driving period in the idle mode and reducing some operations related to a display function.

Description

{TOUCH DRIVING CIRCUIT, TOUCH DISPLAY DEVICE, AND TOUCH DRIVING METHOD THEREOF}

Embodiments of the present invention relate to a touch driving circuit, a touch display device, and a touch driving method.

As the information society develops, the demand for display devices for displaying images is increasing in various forms, and recently, various display devices such as liquid crystal displays, plasma display panels, and organic light emitting diode displays are being utilized.

Meanwhile, in order to provide a touch input function in a display device, an in-cell type touch display device that embeds elements that constitute a touch screen inside the display panel has been developed and used to make portable terminals such as smartphones and tablet PCs slimmer.

The touch function for a touch display device may utilize not only a passive stylus, such as a finger, but also an active stylus that can transmit and receive signals with the display panel.

These touch display devices must perform not only the display function of images but also the touch sensing function, and in particular, a separate synchronization process is required for touch sensing for the active stylus.

In this way, since the touch display device simultaneously performs display functions and touch sensing functions, and power consumption increases due to processes such as synchronization with an active stylus, a method for reducing power consumption of the touch display device is required.

Embodiments of the present invention can provide a touch driving circuit, a touch display device, and a touch driving method that can be divided into an active mode and an idle mode according to a touch sensing type and reduce power consumption in the idle mode.

In addition, embodiments of the present invention can provide a touch driving circuit, a touch display device, and a touch driving method that can reduce power consumption by shortening a touch driving period in an idle mode.

In addition, embodiments of the present invention can provide a touch driving circuit, a touch display device, and a touch driving method that can reduce power consumption by shortening a touch driving period in an idle mode while reducing some operations related to a display function.

In one aspect, embodiments of the present invention can provide a touch display device including a display panel including a plurality of touch electrodes, a touch driving circuit that detects the presence or absence of a touch or a touch position based on a touch sensing signal received from the plurality of touch electrodes and is divided into a first mode and a second mode according to a touch sensing type, and a timing controller that generates a touch synchronization signal such that a touch driving period in the second mode is shorter than a touch driving period in the first mode, and supplies the signal to the touch driving circuit.

In one aspect, a touch display device can be provided in which the first mode is a mode for detecting a touch position, and the second mode is a mode for detecting the presence or absence of a touch.

In one aspect, the second mode can provide a touch display device that simultaneously applies the same touch driving signal to multiple touch electrodes.

In one aspect, the second mode can provide a touch display device in which at least some of the touch sensing functions performed in the first mode are limited.

In one aspect, in the case of LHB driving in which two or more of the touch driving periods are included within one display frame period, a first mode may include two or more of the touch driving periods within one display frame period, and a second mode may include a smaller number of touch driving periods than the first mode within one display frame period, thereby providing a touch display device.

In one aspect, the second mode can provide a touch display device including one touch driving period within one display frame period.

In one aspect, the touch driving period can provide a touch display device having the same time interval in the first mode and the second mode.

In one aspect, the timing controller can provide a touch display device that turns off a memory for temporarily storing digital image data supplied to the display panel in a second mode.

In one aspect, a timing controller can provide a touch display device that transmits data packets to a touch driving circuit through a point-to-point interface, wherein the data packets are transmitted through paired signal lines in a first mode, and the data packets are transmitted through one of the paired signal lines in a second mode.

In one aspect, the timing controller can provide a touch display device that turns off at least some of the power control signals transmitted to the touch driving circuit in the first mode in the second mode.

In one aspect, a touch display device can be provided in which an uplink signal is transmitted from a display panel to a stylus in a first touch driving period in a second mode, and a downlink signal is received from the stylus in a second touch driving period.

In one aspect, the uplink signal may provide the touch display device with a beacon signal necessary for driving the stylus and a ping signal for synchronization.

In one aspect, the downlink signal can provide a touch display device with a signal including at least one of position, tilt, and additional information of the stylus.

In another aspect, embodiments of the present invention include a touch sensing circuit that supplies a touch driving signal to a display panel including a plurality of touch electrodes, receives a touch sensing signal received from the plurality of touch electrodes, outputs a mode control signal according to the touch sensing signal, receives a touch synchronization signal that is divided into a first mode and a second mode according to the mode control signal, and detects the presence or absence of a touch or a touch position according to the touch synchronization signal, wherein the touch synchronization signal can provide a touch driving circuit in which a touch driving period in the second mode is shorter than a touch driving period in the first mode.

In another aspect, embodiments of the present invention can provide a touch driving method including a step of receiving a touch sensing signal from a plurality of touch electrodes arranged on a display panel, a step of generating a mode control signal according to the touch sensing signal, a step of outputting a touch synchronization signal that is distinguished into a first mode and a second mode according to the mode control signal, wherein the touch synchronization signal is set such that a touch driving period in the second mode is shorter than a touch driving period in the first mode, and a step of supplying the touch driving signal to the display panel during the touch driving period set according to the touch synchronization signal.

According to embodiments of the present invention, a touch driving circuit, a touch display device, and a touch driving method can be provided, which can be divided into an active mode and an idle mode according to a touch sensing type, and can reduce power consumption in the idle mode.

In addition, according to embodiments of the present invention, a touch driving circuit, a touch display device, and a touch driving method can be provided that can reduce power consumption by shortening a touch driving period in an idle mode.

In addition, according to embodiments of the present invention, a touch driving circuit, a touch display device, and a touch driving method can be provided that can reduce power consumption by shortening a touch driving period in an idle mode and reducing some operations related to a display function.

FIG. 1 is a schematic drawing of a touch display device according to embodiments of the present invention.
FIG. 2 is an exemplary diagram showing the timing of a display driving period and a touch driving period in a touch display device according to embodiments of the present invention.
FIG. 3 is a drawing illustrating an example of a concept in which an active mode and an idle mode are switched according to a touch sensing type in a touch display device according to embodiments of the present invention.
FIG. 4 is an exemplary drawing showing a case where the touch driving periods of the active mode and the idle mode are set differently in a touch display device according to embodiments of the present invention.
FIG. 5 is an exemplary diagram showing the timing of LHB driving in a touch display device according to embodiments of the present invention.
FIG. 6 is an exemplary diagram showing touch driving timing independent of display driving timing in a touch display device according to embodiments of the present invention.
FIG. 7 is an exemplary drawing showing a case in which the touch driving periods of the active mode and the idle mode are set differently in the case of LHB driving in a touch display device according to embodiments of the present invention.
FIG. 8 is a structure showing an example of a point-to-point interface in a touch display device according to embodiments of the present invention.
FIG. 9 is a drawing showing an example of a signal waveform transmitted in a point-to-point interface in a display device according to embodiments of the present invention.
FIG. 10 is an exemplary diagram of signal waveforms comparing operations in active mode and idle mode in a touch display device according to embodiments of the present invention.
FIG. 11 is a diagram illustrating the operation between a touch display device and a stylus according to embodiments of the present invention.
FIG. 12 is a drawing showing an example of timing at which touch operation for a stylus is performed in idle mode in a touch display device according to embodiments of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. When adding reference numerals to components of each drawing, the same components may have the same numerals as much as possible even if they are shown in different drawings. In addition, when describing the present invention, if it is determined that a specific description of a related known configuration or function may obscure the gist of the present invention, the detailed description may be omitted. When "includes," "has," "consists of," etc. are used in this specification, other parts may be added unless "only" is used. When a component is expressed in the singular, it may include a case where it includes plural unless there is a special explicit description.

In addition, when describing components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components, and the nature, order, sequence, or number of the components are not limited by these terms.

In a description of the positional relationship of components, when it is described that two or more components are "connected", "coupled" or "connected", it should be understood that the two or more components may be directly "connected", "coupled" or "connected", but the two or more components and another component may be further "interposed" to be "connected", "coupled" or "connected". Here, the other component may be included in one or more of the two or more components that are "connected", "coupled" or "connected" to each other.

In the description of the temporal flow relationship related to components, operation methods, or manufacturing methods, for example, when the temporal chronological relationship or the chronological flow relationship is described as "after", "following", "next to", or "before", it can also include cases where it is not continuous, as long as "immediately" or "directly" is not used.

Meanwhile, when a numerical value or its corresponding information (e.g., level, etc.) for a component is mentioned, even if there is no separate explicit description, the numerical value or its corresponding information may be interpreted as including an error range that may occur due to various factors (e.g., process factors, internal or external impact, noise, etc.).

FIG. 1 is a schematic drawing of a touch display device according to embodiments of the present invention.

Referring to FIG. 1, a touch display device (100) according to embodiments of the present invention is a display device that can provide not only an image display function, but also a touch sensing function for a passive stylus such as a finger, and a touch sensing function (stylus recognition function) for an active stylus such as a pen.

A touch display device (100) according to the present embodiments is a display device in which a touch screen panel (TSP) including a plurality of touch electrodes (TE) as touch sensors is built into a display panel (110), and may be a television (TV), a monitor, or a mobile device such as a tablet or smart phone.

For example, the touch display device (100) may block a plurality of common electrodes used for display driving and use them as touch electrodes (TE). As another example, the touch display device (100) may use a plurality of touch electrodes (TE) as touch sensing-only electrodes or touch driving-only electrodes.

The display panel (110) may be a variety of types of panels, such as a liquid crystal display panel or an organic light-emitting display panel.

For example, when the display panel (110) is a liquid crystal display panel, the touch display device (100) can utilize a plurality of blocks of common electrodes, to which a common voltage is applied to form an electric field with pixel electrodes, as touch electrodes (TE).

As another example, when the display panel (110) is an organic light emitting display panel, the touch display device (100) may include a first electrode constituting an organic light emitting diode, an organic light emitting layer, a second electrode, an encapsulation layer positioned thereon and having a sealing function, and a touch sensor metal layer positioned thereon, and a plurality of touch electrodes (TE) may be formed on the touch sensor metal layer.

Below, for convenience of explanation, it is assumed that multiple touch electrodes (TEs) are used as touch driving electrodes (touch sensing electrodes) during the touch driving process and as common electrodes during the display driving process.

A touch display device (100) may include a touch driving circuit (TIC) that performs finger sensing and stylus sensing by using signals received through the display panel (110) by driving a display panel (110) having a built-in touch screen panel (TSP).

Such a touch driving circuit (TIC) may include a first circuit that drives a display panel (110) and receives a signal through the display panel (110), and a second circuit that performs finger touch sensing and stylus touch sensing using the signal received through the display panel (110). In this case, the first circuit is referred to as a touch sensing circuit (ROIC), and the second circuit is also referred to as a touch controller (TCR).

The touch sensing circuit (ROIC) may be implemented as an integrated driver circuit (SRIC) together with a data driver circuit (SDIC) that drives the data lines.

The integrated driver circuit (SRIC) can be a COF (Chip On Film) type mounted on a film.

A film having an integrated driving circuit (SRIC) mounted thereon can be bonded to each of a bonding portion of a display panel (110) and a bonding portion of a printed circuit board (PCB).

A touch controller (TCR), etc. can be mounted on a printed circuit board (PCB).

The touch sensing circuit (ROIC) and the data driving circuit (SDIC) may be implemented as separate driving chips. The touch sensing circuit (ROIC) may be electrically connected to a plurality of touch electrodes (TE) forming the display panel (110) and a plurality of signal lines (SL).

At this time, the touch sensing circuit (ROIC) may perform touch sensing in a touch driving period that is time-divided separately from the display driving period, or the touch driving period that performs touch sensing may proceed simultaneously with the display driving period.

Additionally, the touch display device (100) may include a timing controller (not shown) that controls a touch driver circuit (TIC).

The timing controller can generate a touch synchronization signal that controls a touch driver circuit (TIC). The timing controller sends and receives touch driver signals, etc. based on an interface defined between it and the touch driver circuit (TIC).

Here, the micro control unit (150) may be formed in the form of a single integrated circuit together with the touch controller within the touch circuit (200), or may be formed in the form of a single integrated circuit together with the timing controller (140).

The timing controller receives timing signals such as a vertical sync signal, a horizontal sync signal, a data enable signal, a main clock, and digital image data from a host system (not shown).

The timing controller controls the scan timing of the gate driving circuit (not shown) based on scan timing control signals such as a gate start pulse, a gate shift clock, and a gate output enable signal. In addition, the timing controller controls the data timing of the data driving circuit (SDIC) based on data timing control signals such as a source sampling clock and a source output enable signal.

FIG. 2 is an exemplary diagram showing the timing of a display driving period and a touch driving period in a touch display device according to embodiments of the present invention.

Referring to FIG. 2, a touch display device (100) according to embodiments of the present invention can perform display driving for displaying an image during a display driving period (DP) determined within one display frame period (Display Frame), and perform touch driving for sensing a touch input by a finger or stylus during a touch driving period (TP).

This touch display device (100) uses a common electrode for driving each pixel as an electrode for touch detection. Therefore, during the display driving period (DP), a common voltage is provided to the thin film transistor, and during the touch driving period (TP), a touch driving signal is provided to the common electrode that operates as a touch electrode.

The display driving period (DP) and the touch driving period (TP) may be temporally identical or overlapping periods, or may be temporally separate periods.

When the display driving period (DP) and the touch driving period (TP) are temporally separated, it can be called time division driving.

On the other hand, if the display driving period (DP) and the touch driving period (TP) are temporally identical, display driving and touch driving can be performed simultaneously, and this driving method can be called time free driving.

In the case of time-division driving, the display driving period (DP) and the touch driving period (TP) can be alternated.

In this way, when the display driving period (DP) and the touch driving period (TP) are alternately and temporally separated, the touch driving period (TP) may correspond to a blank period (Blank) in which display driving is not performed.

Meanwhile, the touch display device (100) can identify or control the display driving period (DP) and the touch driving period (TP) by generating a touch synchronization signal (Tsync) that swings between high and low levels. That is, the touch synchronization signal (Tsync) can be a timing control signal that defines the touch driving period (TP).

For example, a high level section (or low level section) of a touch synchronization signal (Tsync) may correspond to a display driving period (DP), and a low level section (or high level section) of the touch synchronization signal (Tsync) may correspond to a touch driving period (TP).

In this case, the touch sensing circuit (ROIC) applies a touch driving signal to the touch electrode (TE) during a touch driving period (TP) in which the touch synchronization signal (Tsync) is at a low level, and can sense the presence or absence of a touch and the touch position of a passive stylus or an active stylus by using the touch signal received from the touch electrode (TE).

Meanwhile, with respect to a method of allocating a display driving period (DP) and a touch driving period (TP) within one display frame period (Display Frame), for example, one display frame period (Display Frame) may be divided into one display driving period (DP) and one touch driving period (TP), display driving may be performed during one display driving period (DP), and touch driving for sensing touch input by a passive stylus and an active stylus may be performed during one touch driving period (TP) corresponding to a blank period (Blank).

That is, the touch display device (100) can be driven for touch once during a display frame period (Display Frame), which is one cycle of the screen change cycle (Refresh Rate) or frame frequency of the display panel (110).

For example, when the frame frequency is 60 Hz, after display driving is performed to turn on or off pixels through N gate lines constituting the display panel (110) within a horizontal period of 1/60 s, a touch driving period (TP) for touch sensing is performed for a certain interval. In this case, the touch detection frequency (Touch Report Rate) will be 60 Hz.

As another example, one display frame period (Display Frame) may be divided into two or more display driving periods (DP) and two or more touch driving periods (TP), and display driving may be performed during two or more display driving periods (DP) within one display frame period (Display Frame), and touch driving may be performed to sense touch input by a passive stylus and an active stylus in the entire screen area or a part of the screen area once or twice or more during the two or more touch driving periods (TP).

In this way, when display driving and touch driving are performed by dividing one display frame period (Display Frame) into two or more display driving periods (DP) and two or more touch driving periods (TP), each of two or more blank periods (Blank) corresponding to two or more touch driving periods (TP) within one display frame period (Display Frame) is called a Long Horizontal Blank (LHB).

Accordingly, two or more periods during which touch sensing for a stylus or finger is performed within a display frame period (Display Frame) can be referred to as an LHB or touch driving period (TP), and touch driving performed during two or more LHBs within one display frame period (Display Frame) is referred to as “driving.”

The touch display device (100) of the present invention can reduce power consumption by dividing the touch sensing mode into an active mode and an idle mode according to the touch sensing type and varying the touch driving period according to the touch sensing mode.

FIG. 3 is a drawing illustrating an example of a concept in which an active mode and an idle mode are switched according to a touch sensing type in a touch display device according to embodiments of the present invention.

Referring to FIG. 3, a touch display device (100) according to embodiments of the present invention can be divided into an idle mode that detects whether an object (stylus or finger) touches a display panel (110), and an active mode that detects a touch position of an object (stylus or finger) and senses information transmitted by a stylus.

At this time, the operation mode distinguished according to the touch sensing type may be expressed in various terms other than the active mode and the idle mode. In addition, the mode for detecting the presence or absence of a touch is expressed as the idle mode, and the mode for detecting the touch position is expressed as the active mode. However, in the case where the touch display device (100) provides multiple touch sensing functions, the case where the entire touch sensing function (e.g., the presence or absence of a touch, the touch position, the touch pressure, etc.) is performed may be expressed as the active mode, and the case where power consumption is reduced by performing only some of the entire touch sensing functions may be expressed as the idle mode.

For example, in the active mode, by applying different touch driving signals to the plurality of touch electrodes (TE) constituting the display panel (110) or by varying the time at which the touch driving signals are applied, it will be possible to detect the touch position using the touch sensing signal transmitted from the touch electrodes (TE). In addition, in the idle mode, it will be possible to detect the presence or absence of a touch by applying the same touch driving signal to the plurality of touch electrodes (TE) constituting the display panel (110) or by applying the touch driving signals simultaneously.

In short, active mode and idle mode can be viewed as the first and second modes, respectively, which differ in the type of touch in which sensing takes place.

When a touch of an object is detected in the idle mode, the touch display device (100) can change to the active mode after a certain period of time to sense the touch position. In the idle mode, the touch display device (100) periodically or aperiodically searches whether an object touch input has occurred when an object is adjacent to the display panel (110), and if a touch of the object is detected, the touch electrode (TE) corresponding to the area where the touch of the object is detected among the display area of the display panel (110) can be intensively sensed, or can enter the active mode in which not only the touch position of the object but also information transmitted by the stylus in the case of an active stylus can be sensed.

In addition, the touch display device (100) may be driven by changing back to the idle mode when the position of an object is not detected or the output signal of the stylus is not sensed for a predetermined time during the active mode. At this time, the touch display device (100) may be driven by changing back to the active mode when an object is detected during the idle mode.

In addition, the touch display device (100) can be driven while continuously maintaining the active mode even when a touch signal by a finger is not detected if an output signal of the stylus is continuously detected during the active mode.

In addition, the touch display device (100) may have a time or number of touch sensing operations for sensing a touch on an object in the active mode longer than the time or number of touch sensing operations for sensing a touch on an object in the idle mode. That is, in the active mode, more time may be required to sense a touch position on an object or detect an output signal of a stylus, so more touch sensing time may be allocated, and in the idle mode, relatively less touch sensing time may be allocated for detecting whether or not an object is touched.

In this way, the touch display device (100) of the present invention can reduce power consumption by dividing it into an active mode and an idle mode according to the touch sensing type and setting the touch driving period of the idle mode to be shorter than the touch driving period of the active mode.

Below, we will explain an example of detecting the touch position of an object in active mode and detecting whether an object is touched in idle mode.

FIG. 4 is an exemplary drawing showing a case where the touch driving periods of the active mode and the idle mode are set differently in a touch display device according to embodiments of the present invention.

Referring to FIG. 4, a touch display device (100) according to embodiments of the present invention can perform display driving for displaying an image during a set display driving period (DPa, DPi) within one display frame period (Display Frame), and perform touch driving for sensing a touch input by an object (finger or stylus) during a set touch driving period (TPa, TPi).

When the display driving period (DPa, DPi) and the touch driving period (TPa, TPi) are alternately and temporally separated, the touch driving period (TPa, TPi) may correspond to a blank period (Blank) in which display driving is not performed.

At this time, the touch display device (100) can control the display driving period (DPa, DPi) and the touch driving period (TPa, TPi) by supplying a touch synchronization signal (Tsync) that swings between high and low levels from the timing controller to the touch driving circuit (TIC).

For example, a high level section of a touch synchronization signal (Tsync) may correspond to a display driving period (DPa, DPi), and a low level section of a touch synchronization signal (Tsync) may correspond to a touch driving period (TPa, TPi).

Accordingly, the touch driving circuit (TIC) can sense whether an object is touched or the touch position by applying a touch driving signal to the touch electrode (TE) during a touch driving period (TPa, TPi) in which the touch synchronization signal (Tsync) is at a low level and using a touch sensing signal received from the touch electrode (TE).

At this time, the touch display device (100) of the present invention can control differently the touch driving period (TPa) in the active mode in which detection of the touch position is performed and the touch driving period (TPi) in the idle mode in which the presence or absence of a touch is detected.

For example, the touch display device (100) of the present invention may have a touch driving period (TPi) in the idle mode set shorter than the touch driving period (TPa) in the active mode. In this case, if one display frame period (Display Frame) is the same, the display driving period (DPa) in the active mode will be longer than the display driving period (DPi) in the idle mode.

Accordingly, power consumption due to display operation in idle mode may increase, but since power consumption due to touch operation decreases, the overall power consumption of the touch display device (100) may decrease.

In this way, the driving method of differentiating the touch driving periods (TPa, TPi) in the active mode and the idle mode can also be applied to LHB driving in which two or more touch driving periods are performed within one display frame period (Display Frame).

FIG. 5 is an exemplary diagram showing the timing of LHB driving in a touch display device according to embodiments of the present invention.

Referring to FIG. 5, in a touch display device (100) according to embodiments of the present invention, one display frame period (Display Frame) can be time-divided into 16 display driving periods (DP1 to DP16) and 16 touch driving periods (TP1 to TP16).

In this case, 16 touch driving periods (TP1 to TP16) can correspond to 16 LHBs (LHB1 to LHB16).

At this time, the touch display device (100) can alternately perform display driving and touch driving by dividing one display frame period (Display Frame) into one or more display driving periods (DP1 to DP16) and one or more touch driving periods (TP1 to TP16).

Alternatively, the touch driving period (TP1 to TP16) may proceed independently from the display driving period (DP1 to DP16).

FIG. 6 is an exemplary diagram showing touch driving timing independent of display driving timing in a touch display device according to embodiments of the present invention.

Referring to FIG. 6, in the touch display device (100) according to embodiments of the present invention, display driving and touch driving may be performed at different times, but display driving and touch driving may also be performed simultaneously.

Therefore, the touch synchronization signal (Tsync) can play a role in distinguishing between the display driving period (DP) and the touch driving period (TP), or can distinguish and instruct only the touch driving period (TP).

For example, 16 LHBs (LHB1 to LHB16) may be one touch frame period (Touch Frame). Here, the touch frame period (Touch Frame) may mean a period during which a touch by an object (finger or stylus) can be sensed once on the entire screen area of the display panel (110).

Although it is exemplified here that touch driving is performed in the high level section of the touch synchronization signal (Tsync), touch driving may also be performed in the low level section of the touch synchronization signal (Tsync).

Meanwhile, in 16 LHBs (LHB1 to LHB16), touch actuation may be performed to sense a touch by a finger, or touch actuation may be performed to sense a touch by a stylus.

The touch display device (100) of the present invention can reduce power consumption by dividing the touch sensing type into an active mode and an idle mode and setting the touch driving period of the idle mode to be shorter than the touch driving period of the active mode, even in the case of LHB driving in which two or more touch driving periods are performed within one display frame period.

FIG. 7 is an exemplary drawing showing a case in which the touch driving periods of the active mode and the idle mode are set differently in the case of LHB driving in a touch display device according to embodiments of the present invention.

Referring to FIG. 7, a touch display device (100) according to embodiments of the present invention can perform display driving for displaying an image during a set display driving period (DPa, DPi) within one display frame period (Display Frame), and perform touch driving for sensing a touch input by an object (finger or stylus) during a set touch driving period (TPa, TPi).

When the display driving period (DPa, DPi) and the touch driving period (TPa, TPi) are alternately and temporally separated, the touch driving period (TPa, TPi) may correspond to a blank period (Blank) in which display driving is not performed.

For LHB driving, one display frame period (Display Frame) can be time-divided into 16 display driving periods (DP1 to DP16) and 16 touch driving periods (TP1 to TP16). In this case, the 16 touch driving periods (TP1 to TP16) can correspond to 16 LHBs (LHB1 to LHB16).

At this time, the touch display device (100) can alternately perform display driving and touch driving by dividing one display frame period (Display Frame) into one or more display driving periods (DP1 to DP16) and one or more touch driving periods (TP1 to TP16).

At this time, the touch display device (100) can control the display driving period (DPa, DPi) and the touch driving period (TPa, TPi) by supplying a touch synchronization signal (Tsync) that swings between high and low levels from the timing controller to the touch driving circuit (TIC).

For example, a high level section of a touch synchronization signal (Tsync) may correspond to a display driving period (DPa, DPi), and a low level section of a touch synchronization signal (Tsync) may correspond to a touch driving period (TPa, TPi).

Accordingly, the touch driving circuit (TIC) can sense whether an object is touched or the touch position by applying a touch driving signal to the touch electrode (TE) during a touch driving period (TPa, TPi) in which the touch synchronization signal (Tsync) is at a low level and using a touch sensing signal received from the touch electrode (TE).

At this time, the touch display device (100) of the present invention can control differently the touch driving period (TPa) in the active mode in which detection of the touch position is performed and the touch driving period (TPi) in the idle mode in which the presence or absence of a touch is detected.

For example, the touch display device (100) of the present invention may include touch driving periods (TPa) corresponding to 16 LHBs (LHB1 to LHB16) in the active mode, but may include only a touch driving period (TPi) corresponding to one LHB in the idle mode. Of course, the touch driving period (TPi) in the idle mode may correspond to one LHB or may correspond to two or more LHBs. However, the touch driving period (TPi) in the idle mode will have a shorter interval than the touch driving period (TPa) in the active mode.

In this case, if one display frame period (Display Frame) is the same, the display driving period (DPa) in active mode will be greater than the display driving period (DPi) in idle mode.

Meanwhile, the touch driving period (TPi) included in the idle mode may have a time interval that is the same as or an integer multiple of the LHB in the active mode, but may also be set to a time interval that is not an integer multiple of the LHB.

Accordingly, power consumption due to display operation in idle mode may increase, but since power consumption due to touch operation decreases, the overall power consumption of the touch display device (100) may decrease.

Meanwhile, the touch display device (100) of the present invention can reduce power consumption required for touch driving by reducing the touch driving period (TPi) in idle mode, and can also reduce power consumption required for display driving by limiting some of the display driving operations required to display an image on the display panel (110).

FIG. 8 is a structure showing an example of a point-to-point type interface in a touch display device according to embodiments of the present invention, and FIG. 9 is a drawing showing an example of a signal waveform transmitted in a point-to-point type interface in a display device according to embodiments of the present invention.

Referring to FIGS. 8 and 9, a touch display device (100) according to embodiments of the present invention may include a timing controller (140) that transmits a plurality of data packets (PD1, PD2), a plurality of integrated driving circuits (SRIC1 to SRICn) that receive a plurality of data packets (PD1, PD2) transmitted from the timing controller (140), and a touch controller (TCR) that controls the plurality of integrated driving circuits (SRIC1 to SRICn) and performs touch sensing using a touch sensing signal received through a display panel (110).

The interface standard exemplified here is an embedded point-to-point interface (EPI) that serializes data control signals and digital image data, inserts clock information, and transmits data packets (PD1, PD2) in packet units to reduce the number of data transmission lines and enable high-speed transmission between a timing controller (140) and an integrated driving circuit (SRIC1 to SRICn).

In addition, a structure is described as an example in which data packets (PD1, PD2) are transmitted through a pair of signal lines from a timing controller (140), and data packets (PD1, PD2) are received from two integrated driving circuits (SRIC1, SRIC2), respectively, and supplied to a display panel (110).

The timing controller (140) can transmit data packets (PD1, PD2) to the corresponding integrated driving circuits (SRIC1, SRIC2) according to the clock signal (CLK).

At this time, the data packet (PD1, PD2) transmitted by the timing controller (140) is transmitted through a pair of signal lines, and can be divided into a first transmission period, a second transmission period, and a third transmission period.

In the first transmission period, clock training is performed to synchronize a clock signal (CLK) using a clock training pattern (CT), in the second transmission period, a data control signal (DCS) for controlling an integrated driving circuit (SRIC1, SRIC2) is transmitted, and in the third transmission period, digital image data (DATA) can be transmitted. However, the section in which data packets (PD1, PD2) are transmitted and the type of data transmitted can be expressed in various ways.

The timing controller (140) can synchronize the clock signal (CLK) by performing clock training with the integrated driving circuits (SRIC1, SRIC2) during the clock training time (Tct) within the horizontal blank period (Horizontal Blank Time) or the vertical blank period (Vertical Blank Time).

The timing controller (140) can transmit a lock input signal (Lock(IN)) to the first integrated driving circuit (SRIC1) while being synchronized with the integrated driving circuits (SRIC1, SRIC2) through clock training. In addition, the timing controller (140) can receive a lock output signal (Lock(OUT)) as feedback from the second integrated driving circuit (SRIC2).

The first integrated driver circuit (SRIC1) generates a lock signal (Lock) of a high logic level, indicating an output stable state, when the phase of the internal clock signal is fixed, and transmits it to the adjacent second integrated driver circuit (SRIC2).

At this time, the lock signal (Lock) generated from the second integrated driver circuit (SRIC2) becomes the lock output signal (Lock(OUT)) of the integrated driver circuit, and the lock output signal (Lock(OUT)) is transmitted to the timing controller (140) through a signal line connected between the timing controller (140) and the last integrated driver circuit (SRIC2). At this time, a high-level DC power supply voltage (VCC) is input to the lock signal (Lock(IN), Lock) input terminal of the integrated driver circuits (SRIC1, SRIC2).

When a normal lock output signal (Lock(OUT)) is received from the second integrated driving circuit (SRIC2), the timing controller (140) can transmit data packets (PD1, PD2) corresponding to each of the plurality of integrated driving circuits (SRIC1, SRIC2).

At this time, the embedded point-to-point interface (EPI) standard may not use wiring for transmitting a clock signal (CLK) between the timing controller (140) and the integrated driver circuits (SRIC1, SRIC2) in order to reduce signal lines. In this case, when the timing controller (140) transmits a data packet (PD1, PD2), the integrated driver circuits (SRIC1, SRIC2) can generate an internal clock signal using the transmitted data packet (PD1, PD2) and receive digital image data (DATA) in response to the generated internal clock signal.

At this time, the integrated driving circuit (SRIC1, SRIC2) can compare the internal clock signal with the clock training pattern transmitted from the timing controller (140), and if there is no abnormality in the comparison result, it can generate a high level lock signal (Lock) or transmit a lock output signal (Lock (OUT)) to the timing controller (140).

Meanwhile, the lock output signal (Lock (OUT)) transmitted from the second integrated driving circuit (SRIC2) to the timing controller (140) may be a signal that feeds back the lock input signal (Lock (IN)) transmitted from the timing controller (140) to the first integrated driving circuit (SRIC1).

In a state where a lock output signal (Lock(OUT)) is transmitted to the timing controller (140), the integrated driving circuit (SRIC1, SRIC2) can fix the phase and frequency of the synchronized data packet (PD1, PD2) through clock training, and thus can receive the data packet (PD1, PD2) transmitted from the timing controller (140).

At this time, when using a point-to-point interface, the timing controller (140) can control the output characteristics of the data packets (PD1, PD2) to be transmitted according to the connection status or signal transmission characteristics with the integrated driving circuit (SRIC1, SRIC2).

At this time, the touch display device (100) of the present invention can reduce power consumption in the idle mode by making the data packets (PD1, PD2) transmitted from the timing controller (140) to the integrated driving circuits (SRIC1, SRIC2) different depending on the active mode and the idle mode.

For example, the timing controller (140) can reduce power consumption by simultaneously transmitting data packets (PD1, PD2) through paired signal lines in active mode, but transmitting data packets (PD1 or PD2) through one signal line in idle mode.

At this time, since the touch controller (TCR) can control the active mode and the idle mode according to the touch sensing type for the display panel (110), the timing controller (140) can control the data packets (PD1, PD2) transmitted to the integrated driving circuits (SRIC1, SRIC2) by receiving the mode control signal (MCS) from the touch controller (TCR).

In addition, the touch display device (100) of the present invention can reduce power consumption by not only partially limiting data packets (PD1, PD2) transmitted to the integrated driving circuit (SRIC1, SRIC2) in idle mode, but also turning off a memory storing digital image data (DATA) or turning off some power control signals included in a data control signal (DCS).

For example, the touch display device (100) of the present invention can control the memory that stores digital image data (DATA) to be turned on in the active mode and the memory to be turned off in the idle mode so that the digital image data (DATA) is directly transmitted to the integrated driving circuit (SRIC1, SRIC2).

Meanwhile, a data control signal (DCS) transmitted to control the integrated driving circuit (SRIC1, SRIC2) in the second transmission period may include a polarity control signal, a charge sharing option signal, a polarity period control signal of digital image data (DATA), a power control signal of the integrated driving circuit (SRIC1, SRIC2), a channel selection signal of the integrated driving circuit (SRIC1, SRIC2), etc.

Accordingly, the touch display device (100) of the present invention can reduce power consumption due to display driving by limiting some of the power control signals, such as the power control signal or the channel selection signal, among the data control signals (DCS) transmitted to the integrated driving circuit (SRIC1, SRUC2) in idle mode.

FIG. 10 is an exemplary diagram of signal waveforms comparing operations in active mode and idle mode in a touch display device according to embodiments of the present invention.

Referring to FIG. 10, a touch display device (100) according to embodiments of the present invention can be divided into an active mode and an idle mode according to a mode control signal (MCS) generated by a touch controller (TCR).

The idle mode may be an operation mode capable of detecting whether an object (stylus or finger) is touching the display panel (110), and the active mode may be an operation mode capable of detecting the touch position of the object (stylus or finger) and sensing information transmitted by the stylus.

Alternatively, the touch display device (100) may be classified as an active mode in which the entire touch sensing function (e.g., touch presence, touch location, touch pressure, etc.) is performed, and an idle mode in which power consumption is reduced by performing only some of the entire touch sensing functions.

The active mode and idle mode can be determined by the mode control signal (MCS) generated from the touch controller. For example, when the mode control signal (MCS) is at a high level, it can operate in the active mode, and when it is at a low level, it can operate in the idle mode.

When a touch sensing operation is performed in a blank period, the timing controller (140) can generate a touch driving signal (Tsync(BS)) to have a touch driving period of A hours in one display frame period in the active mode, but to have a touch driving period of B hours, which is smaller than A hours, in the idle mode.

At this time, since the display frame periods of the active mode and the idle mode are the same, the touch driving period of the idle mode is reduced compared to the active mode, but the display driving period of the idle mode can be increased compared to the active mode.

In addition, in the case of LHB driving including multiple touch driving periods in one display frame period, the timing controller (140) may generate the touch driving signal (Tsync(LHB)) so that one display frame period has A number of touch driving periods in the active mode, but B number of touch driving periods less than A number of times in the idle mode. At this time, the touch driving period in the idle mode may be the same as or different from the touch driving period in the active mode.

At this time, since the display frame periods of the active mode and the idle mode are the same, the touch driving period of the idle mode within one display frame period may be reduced compared to the active mode, but the display driving period of the idle mode may be increased compared to the active mode.

In addition, the timing controller (140) of the touch display device (100) stores digital image data (DATA) in memory for a certain period of time in the active mode and then transmits it to the integrated driving circuit (SRIC), but in the idle mode, it turns off the memory and transmits the digital image data (DATA) directly to the integrated driving circuit (SRIC), thereby reducing power consumption due to memory operation.

In addition, the timing controller (140) of the touch display device (100) transmits data packets (PD) to the integrated driving circuit (SRIC) through paired signal lines in the active mode, but transmits data packets (PD) to the integrated driving circuit (SRIC) through one of the paired signal lines in the idle mode, thereby reducing power consumption due to transmission of the data packets (PD).

In addition, the timing controller (140) of the touch display device (100) can reduce power consumption due to transmission of data packets (PD) by blocking some of the power control signals among the data control signals (DCS) constituting the data packets (PD) to a low level in idle mode.

In addition, the touch display device (100) of the present invention can perform a synchronization process of an active stylus in an idle mode with a shortened touch driving period.

FIG. 11 is a diagram illustrating the operation between a touch display device and a stylus according to embodiments of the present invention.

Referring to FIG. 11, a touch display device (100) according to embodiments of the present invention transmits an uplink signal including various information for controlling driving of a stylus or various information necessary for driving of the stylus to the stylus during a touch driving period for stylus touch sensing.

More specifically, a touch driving circuit (TIC) of a touch display device (100) supplies an uplink signal including various information for controlling the driving of a stylus or various information necessary for driving the stylus to one or more of a plurality of touch electrodes (TE) included in a display panel (110).

Accordingly, a stylus adjacent to the display panel (110) can receive an uplink signal through the stylus tip. That is, the stylus can receive an uplink signal through one or more of a plurality of touch electrodes (TE) included in the display panel (110).

Additionally, the stylus outputs a downlink signal indicating the position, tilt, or various additional information of the stylus in response to an uplink signal transmitted from the touch display device (100).

A downlink signal output from the stylus can be applied to a touch electrode (TE) of the display panel (110).

The touch driving circuit (TIC) of the touch display device (100) receives a downlink signal output from the stylus through a touch electrode (TE), and can obtain the position, tilt, and various additional information of the stylus based on the received downlink signal.

Here, the uplink signal may include, for example, a beacon signal or a ping signal.

A beacon signal is a control signal for the touch display device (100) to control the operation of the stylus or to inform the stylus of necessary information, and may include various types of information necessary for the operation of the stylus.

For example, the beacon signal may include one or more of basic information of the display panel (110) (e.g., status information, identification information, type information such as in-cell type, etc.), driving mode information of the display panel (110) (e.g., mode identification information such as active mode, idle mode, etc.), characteristic information of a downlink signal (e.g., frequency, number of pulses, etc.), driving timing related information, multiplexer driving information, power mode information (e.g., LHB information that the display panel and stylus are not driven to reduce power consumption, etc.), and may further include information for synchronization between the display panel (110) and the stylus.

Ping signal can be a control signal for synchronization of downlink signals.

Additional information that may be included in the downlink signal may include, for example, one or more of pressure, stylus ID, button information, battery information, and error check information.

FIG. 12 is a drawing showing an example of timing at which touch operation for a stylus is performed in idle mode in a touch display device according to embodiments of the present invention.

Referring to FIG. 12, a touch display device (100) according to embodiments of the present invention can be operated in an active mode and an idle mode according to a mode control signal (MCS) generated by a touch controller (TCR).

When a touch sensing operation is performed in a blank period, the timing controller (140) can generate a touch driving signal (Tsync) such that the touch driving period is A hours per one display frame period in the active mode, but the touch driving period is B hours, which is smaller than A hours, in the idle mode.

In addition, in the case of LHB driving including multiple touch driving periods in one display frame period, the timing controller (140) may generate a touch driving signal (Tsync) such that one display frame period has A number of touch driving periods in the active mode, but has B number of touch driving periods, which is less than A number, in the idle mode.

At this time, since the display frame periods of the active mode and the idle mode are the same, the touch driving period of the idle mode within one display frame period may be reduced compared to the active mode, but the display driving period of the idle mode may be increased compared to the active mode.

At this time, the uplink signal transmitted from the display panel (110) to the stylus and the downlink signal transmitted from the stylus to the display panel (110) can be transmitted during the touch driving period in the idle mode, respectively.

*For example, during the first touch operation period after entering the idle mode, a beacon signal, which is one of the uplink signals, may be transmitted from the display panel (110) to the stylus one or more times.

When a beacon signal is transmitted from the display panel (110) to the stylus, the stylus can output a downlink signal for a set touch driving period according to a predefined protocol in response to the beacon signal.

At this time, the downlink signal output from the stylus can be applied to one or more of a plurality of touch electrodes (TE) included in the display panel (110) during the second touch driving period.

That is, the stylus can receive an uplink signal from the display panel (110) during the first touch driving period in the idle mode, and then transmit a downlink signal to the display panel (110) during the second touch driving period.

At this time, if the downlink signal output from the stylus is a downlink signal for the position of the stylus, the downlink signal may be a signal composed of pulses that swing periodically. Alternatively, if the downlink signal output from the stylus is a downlink signal for data of the stylus, the downlink signal may be a signal composed of aperiodic pulses representing the corresponding data.

In this way, the touch display device (100) of the present invention can efficiently perform synchronization with the stylus while reducing power consumption by alternately transmitting an uplink signal transmitted from the stylus to the display panel (110) and a downlink signal transmitted from the stylus to the display panel (110) during the touch driving period while entering the idle mode.

The above description is merely an illustrative description of the technical idea of the present invention, and those skilled in the art will appreciate that various modifications and variations may be made without departing from the essential characteristics of the present invention. In addition, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to explain it, and therefore the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

100: Touch display device
110: Display panel
140: Timing Controller

Claims (13)

A display panel including a plurality of touch electrodes and being divided and driven into at least one display driving period and at least one touch driving period within one display frame period;
A touch driving circuit that detects the presence or absence of a touch or a touch position based on a touch sensing signal received from the plurality of touch electrodes, and is divided into a first mode and a second mode according to the touch sensing type; and
A touch display device including a timing controller that generates a touch synchronization signal and supplies it to the touch driving circuit, the touch driving period in the first mode being different from the touch driving period in the second mode.
In paragraph 1,
The above first mode is a mode for detecting the touch position,
A touch display device in which the second mode is a mode that detects the presence or absence of a touch.
In the second paragraph,
The above first mode is
Sequentially applying a touch driving signal to the above plurality of touch electrodes,
The second mode above is
A touch display device that simultaneously applies the same touch driving signal to a plurality of touch electrodes.
In paragraph 1,
The second mode above is
A touch display device in which at least some of the touch sensing functions performed in the first mode are limited.
In paragraph 1,
In the case of LHB driving where two or more touch driving periods are included within the above one display frame period,
The above first mode includes n (n is a natural number greater than or equal to 2) display driving periods and n touch driving periods within the one display frame period,
The second mode is a touch display device including n display driving periods and m (wherein m is a natural number less than n) touch driving periods within one display frame period.
In paragraph 5,
The above m is a single-touch display device.
In paragraph 1,
The above timing controller
A touch display device that turns off a memory for temporarily storing digital image data supplied to the display panel in the second mode.
In paragraph 1,
The above timing controller
Transmitting data packets to the touch driving circuit via a point-to-point interface,
In the above first mode, the data packet is transmitted through a pair of signal lines,
A touch display device that transmits the data packet through one of the signal lines formed in a pair in the second mode.
In paragraph 1,
The above timing controller
A touch display device that turns off at least some of the power control signals transmitted to the touch driving circuit in the first mode in the second mode.
In paragraph 1,
The above display panel
In the above first mode, an uplink signal is transmitted to the stylus and a downlink signal is received from the stylus within one touch driving period,
A touch display device that transmits an uplink signal to the stylus during a first touch driving period in the second mode and receives a downlink signal from the stylus during a second touch driving period.
In Article 10,
The above uplink signal is
A beacon signal required to drive the above stylus; and
A touch display device including a ping signal for synchronization.
In Article 10,
The above downlink signal is
A touch display device, wherein the signal comprises at least one of position, inclination, and additional information of the stylus.
A touch sensing circuit for supplying a touch driving signal to a display panel including a plurality of touch electrodes and being divided into at least one display driving period and at least one touch driving period within one display frame period, and receiving a touch sensing signal received from the plurality of touch electrodes during the at least one touch driving period; and
A touch controller is included that outputs a mode control signal according to the above touch sensing signal, receives a touch synchronization signal that is divided into a first mode and a second mode according to the above mode control signal, and detects the presence or absence of a touch or a touch position according to the touch synchronization signal.
The above touch synchronization signal
A touch driving circuit in which the touch driving period in the first mode is controlled differently from the touch driving period in the second mode.